The embodiment relates to a backlight unit and a display device.
Generally, Liquid Crystal Displays (LCDs) have higher visibility than Cathode Ray Tubes (CRTs) and less average power consumption and heat emission than the same screen size of CRTs. For this reason, LCDs have been widely used in mobile phones, computer monitors and televisions, along with plasma display devices or field emission display devices.
The driving principle of LCDs is based on optical isotropy and polarization of liquid crystals. Elongated liquid crystals exhibit directivity in molecular arrangement. Here, the molecular arrangement direction of liquid crystals may be controlled by applying an electric field to liquid crystals.
Accordingly, controlling the molecular arrangement direction of liquid crystals may change molecular arrangement of liquid crystals, whereby image information can be displayed as light is refracted in the molecular arrangement direction of liquid crystals by optical isotropy.
However, LCDs are non-self emissive devices and require a separate light source. One example of the light source is a backlight unit. Specifically, light emitted from a backlight unit disposed behind a liquid crystal panel is introduced into the liquid crystal panel, such that transmittance of light is controlled based on the arrangement of liquid crystals, enabling display of an image.